This study investigates bidirectional influences between the development of children's antisocial behavior from 2 to 9 years and two dimensions of authoritative parenting (positive nurturant parenting and appropriate discipline, i.e., consistent, non-hostile, and inductive discipline). The study addresses gaps in our current understanding about preventing early antisocial development by disentangling these bidirectional influences between parents and children. The main analyses follow a cohort of over 2,900 children who were 2 or 3 years old at the beginning of the Canadian National Longitudinal Survey of Children and Youth (NLSCY) and follow them for four waves of data until they were 8 or 9 years old. Analyses control for social disadvantage, parental depression, and family structure. Advantages of the NLSCY for this project include early measures for temperament and positive parent-child interactions (as young as 3 months of age); hyperactivity, aggression, and prosocial behavior (2-year-olds); discipline consistency, parental hostility, and five disciplinary tactics (2-year-olds); and teacher reports of hyperactivity, aggression, prosocial behavior, and academic and social competencies (4 or 5 years old). Dynamic modeling of latent change scores (McArdle & Hamagami, 2001) enable the project to determine how levels of each latent variable (e.g., positive parenting) predict changes in the other latent variables (e.g., antisocial). After identifying bidirectional influences between the major parenting dimensions and early antisocial development, additional analyses investigate generalization of these findings and the specific roles of several disciplinary tactics. These additional analyses include (1) generalization to teacher-reported antisocial behaviors beginning at ages 4 or 5; (2) generalization to bidirectional influences between temperament and parenting dimensions as early as 3 to 23 months of age; and (3) predictions that a combined or balanced use of reasoning and nonphysical punishment reduces subsequent antisocial trajectories more than relatively exclusive use of either tactic alone, especially for difficult preschoolers. Other specific analyses investigate interactive effects consistent with authoritative parenting and convergent/divergent effects comparing nonphysical punishment with physical or verbal punishment.